Thus, I still note the same (second) problem : they appear between Mali & Niger.... :evil: It can't be a projection problem, because this raster has been made by IGN (National Institute of Geography).I think I should forget something during or before the export...So, I've tried to reproject my raster (both session and registered), but nothing seems to work.

Has anybody encountered the same difficulties ?

Thank you again

Gregorx, my scan25 maps both in "Lambert 2 étendu" projection and in Latitude/longitude are falling in the right place in Locus. Maybe Global Mapper has some problem to handle your Lambert 3 projection?